Subject: Lenses Date: Sun, 01 Feb 1998 17:08:13 -0600 From: John Eagle <jwe392@mail.usask.ca> To: hwang@phy03.phy.ntnu.edu.tw I think this page is great. I stumbled into it one night while trying to find some insight on a physics assignment that I had. I've used it ever since to check my work. Something that might be helpful to a great number of people would be a java applet with thick lenses and or two lense systems. Just a thought. Thank you for taking the time to publish such a page John Eagle

Subject: Lens/mirror Date: Fri, 03 Apr 1998 16:16:37 -0600 From: Kelly <kpuls@students.wisc.edu> To: hwang@phy03.phy.ntnu.edu.tw Mr. Hwang, I want to say that your virtual lab was unbelievably helpful to me. I attend the university of wisconsin-madison and I was having problems with optics concepts. I went under the internet and searched under lens and mirrors and fell upon your lab. I am very grateful. I was a little upset last night when I wanted to access the lens mirror applet, because I couldn't find it. I guess even the virtual labs have hours of availability. I guess that's my only suggestion, which isn't a very necessary one to attend to when most of us can access it during the day. Thanks again, Chris cechapma@students.wisc.edu

Subject: Wow!!! Date: Sun, 03 May 1998 15:39:11 -0600 From: The Lahrs To: hwang@phy03.phy.ntnu.edu.tw I just figured out that the inverted image is not virtual but real, so everything makes sense now. Keep up the good work. John C. Lahr

Subject: Wow!!! Date: Sun, 03 May 1998 12:47:55 -0600 From: The Lahrs To: hwang@phy03.phy.ntnu.edu.tw I love your thin lens page: http://www.phy.nau.edu/~layton/JavaApps/thinlens/lens_e.htmWhat a great use of Java! I use Netscape, by the way, and the applet worked just fine and was very speedy. I've been trying to figure out why a glass rod creates an inverted (about one axis) virtual image. Do you have an applet for a thick lens, or just a ray diagram that would show this effect? Is the thinlens.java code still available? The link was not working when I tried. It would be interesting to develop something like this for seismic waves. I'm a seismologist now, but my first love is physics, which was my undergraduate major at Rensselaer Polytechnic Institute. Thanks again for providing the world this great applet. John C. Lahr -- * John C. and Jan H. Lahr * * 914 10th Street * * Golden, Colorado 80401 * * (303) 215-9913 * * http://www.lahr.org/john-jan * * http://giseis.alaska.edu/lahr *

I was looking at your applet for the thin lens and really liked it. I am new to applets and often it is possible to download them so that you can use them off line but I couldn't work out what to do to download your applet.

I am a secondary teacher and would really like to show it to my students. Would I be able to get a copy of it please.

I see mainly converging lenses collecting rays to one poit (pix A) but do they work another direction? (pix B) any differet solutions/ something usefull to know? I know I could use image conduit but they don't have enought resolution for 2000-3000 pixel CCD-bar/21mm wide...or I'm wrong? :?: In pictures arrow shows direction of ray.

Another Q is about focusing. Is there difference in working of D ja C assebly pictures? Are they equal?

[quote:506d759f5b]I see mainly converging lenses collecting rays to one poit (pix A) but do they work another direction? (pix B) any differet solutions/ something usefull to know? I know I could use image conduit but they don't have enought resolution for 2000-3000 pixel CCD-bar/21mm wide...or I'm wrong? In pictures arrow shows direction of ray. [/quote:506d759f5b]Yes. The path of light ray is reversable. If those parallel light really focus on one single point. You can place a light source at that point can create a parallel light output.

When I check it with my browser with two different account. It works fines with my netscape and IE browser.Could you tell me what is your browser and the verson #?We have many downloads per days without such problems.

This app is great. I would like to build off of your code to do a mirror simulation focused on some different ideas, but I don't can't get the app to open in the EJS interface so I can work on it. Is there a way to do this?

Applets under physics simulation category are created many years ago with JDK 1.0.2

Only those applets under "Easy Java SImulation" category are created with ejs. And you can view how it was created.

I am going to change the code and the server structure so that user can also edit ejs code and save the modified simulation on our server . (user also can get modified ejs code and all related files in ZIP format).

This is absolutly spiffingly amazing! It reminds me of things that are good! This is very good program it is good. Not bad.I is a Student at Taira High School in Japan. Arigatoo my freinds.Gomibako ni sunde imasu.Neko o tabemasu ka?Thanks you my freindsMunko? :twisted: